Hydroconversion catalysts and methods of making and using same

ABSTRACT

Stable catalyst carrier impregnating solutions can be prepared using a component of a Group VIB metal, e.g., molybdenum, at high concentration, a component of a Group VIII metal, e.g., nickel, at low concentration, and a phosphorous component, e.g., phosphoric acid, at a low concentration, provided that the Group VIII metal is in a substantially water-insoluble form and a particular sequence of addition of the components is followed, even when a substantially water-insoluble form of the Group VIB component is used. The resulting stabilized impregnating solution can be supplemented with additional Group VIII metal in water-soluble form to achieve increased levels of such metal in the final catalyst. Furthermore, uncalcined catalyst carriers impregnated with the stable solution and subsequently shaped, dried and calcined, have unexpectedly improved performance when used in the hydroprocessing of heavy hydrocarbon feedstocks. High conversion can be achieved at reduced levels of sediment, especially in comparison to standard commercial catalysts.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.10/719,551, filed on Nov. 20, 2003, now U.S. Pat. No. 7,390,766, issuedJun. 24, 2008, the disclosure of which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

This patent relates to catalysts supported on a foraminous carrier andmethods for preparing such catalysts using stabilized aqueouscompositions. In particular, this patent relates to aqueous compositionscontaining catalytically-active metal components and substantially watersoluble acidic components and to the catalysts prepared using suchaqueous compositions for impregnating foraminous carriers. It isdesirable to convert heavy hydrocarbons, such as those having a boilingpoint above about 1000° F., into lighter, and more valuable,hydrocarbons. It is also desirable to treat hydrocarbon feedstocks,particularly petroleum residues, also known as resid feedstocks, inorder to carry out, for example, hydrodesulfurization (HDS),hydrodenitrogenation (HDN), carbon residue reduction (CRR),hydrodemetallation (HDM), including the removal of nickel compounds(HDNi) and vanadium compounds (HDV). The catalysts of the presentinvention are particularly useful and effective in thehydrodesulfurization, hydrodenitrogenation, hydrodemetallation, etc. ofpetroleum compositions, especially high-boiling petroleum compositions.

Catalysts comprising at least one Group VIII metal component, at leastone Group VIB metal component and a phosphorous component, suchcomponents being carried on a foraminous carrier, are known in the art.

It is known that the metals of Group VIB of the periodic table, forexample tungsten and molybdenum, and components comprising such metals,for example compounds such as the oxides and sulfides, are active incatalyzing a wide variety of reactions including among others,hydrogenation, dehydrogenation, oxidation, desulfurization,isomerization and cracking. However, catalytic metals and componentscontaining them are, relatively costly and have a relatively smallsurface area per unit weight, so that they are typically not usedwithout resort to carrier materials. Consequently, these catalyticallyactive metals or components are usually applied in a diluted form to thesurface of a foraminous support material. The foraminous supportmaterial is usually of a low order of activity when compared to thecatalytically-active components, or such carriers may even becatalytically completely inactive.

Furthermore, it is known that certain metal-containing components ofGroup VIII of the periodic table of the elements, such as iron, cobalt,and nickel, when used in combination with the Group VIB metal-containingcomponents, result in enhanced catalytic activity. These Group VIIIcomponents are sometimes referred to as catalyst “promoters.” However,problems can result when these promoters are attempted to be impregnatedinto a carrier along with the catalytically active components of GroupVIB. Simple and direct impregnation techniques using a mixture of bothcomponents typically cannot be employed. For example, a combination ofcomponents based on cobalt or nickel salts with molybdenum or tungstencomponents typically results in unstable solutions, e.g., solutionssubject to the formation of precipitates. Impregnation of a carrierusing separate solutions comprising components of Group VIB and GroupVIII is not an acceptable alternative since that can result in costly,multi-step processes and ineffective or non-uniform metals distribution.

Rather costly and involved processes have been devised in order toobtain a uniform distribution throughout the available surface area ofthe foraminous catalyst carrier material when using componentscontaining both of the catalytically active metals of Group VIB andGroup VIII. It has been the objective of these methods to preparesolutions containing metals of both Group VIB and Group VIII that aresufficiently concentrated and of the requisite stability to allowsubsequent uniform impregnation and distribution of the metalsthroughout and upon the surface area of the carrier. These methodstypically include the use of high concentrations of phosphoric acid.Typically, the carrier is impregnated with a dilute solution comprisinga phosphorous component, although some applications do not use aphosphorous component, and components of metals of both Group VIB andGroup VIII, by applying the solution to a calcined foraminous carriermaterial, and then drying and calcining the composite to convert thecatalytically active material to other forms, particularly to the oxide.However, the use of phosphoric acid, particularly at high concentrationsthat are required to readily solubilize both of the metal containingcomponents and maintain them in a stable solution, can introduceperformance related problems during the use of such catalysts inhydroconversion processes.

Therefore, it would be an advantage to the art to prepare a stableaqueous composition containing metals from both Group VIB and Group VIIIsuitable for use in producing a finished catalyst having desirableperformance characteristics.

Furthermore, as noted, there is increased interest in producing andupgrading lower quality hydrocarbon feeds, such as synthetic crudes andheavy petroleum crude oil fractions. Unfortunately, high concentrationsof nitrogen, sulfur, metals and/or high boiling components, for example,asphaltenes and resins, in such lower quality feeds render the samepoorly suited for conversion to useful products in conventionalpetroleum refining operations. In view of such difficulties, lowerquality hydrocarbon feeds often are catalytically hydrotreated to obtainmaterials having greater utility in conventional downstream refiningoperations. Catalytic hydrotreating or hydroconversion involvescontacting such a feed with hydrogen at elevated temperature andpressure in the presence of suitable catalysts. As a result of suchprocessing, sulfur and nitrogen in the feed are converted largely tohydrogen sulfide and ammonia which are easily removed. Aromaticssaturation and cracking of larger molecules often take place to converthigh boiling feed components to lower boiling components. Metals contentof the feed decreases as a result of deposition of metals on thehydrotreating catalyst.

As can be appreciated, satisfactory operation in processing feedscontaining high levels of impurities under severe process conditionsplaces increased demands on the catalyst to be employed as the same mustexhibit not only high activity in the presence of impurities and undersevere conditions, but also stability and high activity maintenanceduring the time that it is in use. Catalysts containing a Group VIBmetal component, such as a molybdenum and/or tungsten component,promoted by a nickel and/or cobalt component and supported on a porousrefractory inorganic oxide are well known and widely used inconventional hydrotreating processes; however, the same often aresomewhat lacking in stability and activity maintenance under severeconditions.

It is known that preparation of hydrotreating catalysts containing GroupVIB and Group VIII metal components supported on a porous refractoryinorganic oxide can be improved through the use of phosphoric acidimpregnating solutions of precursors to the Group VIB and Group VIIImetal components or the use of phosphoric acid as an impregnation aidfor the metal precursors. Thus, Pessimisis, U.S. Pat. No. 3,232,887discloses stabilization of Group VIB and Group VIII metal-containingsolutions through the use of water-soluble acids. According to thepatentee, in column 3, lines 6-11, “in its broadest aspect the inventioncomprises the preparation of stabilized aqueous solutions which comprisean aqueous solvent having dissolved therein catalytically activecompounds containing at least one element from Group VIB of the periodictable and one element from Group VIII.” Inorganic oxyacids of phosphorusare included among the disclosed stabilizers, and the examples ofPessimisis illustrate preparation of various cobalt-molybdenum,nickel-molybdenum, and nickel-tungsten catalysts using phosphorus andother acids as stabilizers. Hydrodesulfurization results with certain ofthe cobalt-molybdenum catalysts are presented, and the patentee suggeststhat the use of the stabilized solutions may lead to improvedhydrodesulfurization activity in some instances.

Similarly, Colgan et al., U.S. Pat. No. 3,287,280 discloses the use ofphosphoric acid as an impregnation aid in preparation ofnickel-molybdenum catalysts and that such use can result in catalystshaving improved hydrodesulfurization activity.

Colgan et al., U.S. Pat. No. 3,840,472 disclose catalysts prepared byimpregnation of an alumina support with stabilized solutions of molybdicoxide and certain cobalt or nickel salts dissolved in aqueous phosphoricacid although the patentees suggest that the presence of certain amountsof a phosphorus component in the ultimate catalyst may harm performance;see column 2, lines 23-28.

Simpson, U.S. Pat. No. 4,255,282 discloses hydrotreating catalystscomprising molybdenum, nickel, and phosphorus components and agamma-alumina support, such catalysts being prepared by a method thatinvolves a precalcination of the gamma-alumina at a temperature greaterthan 746° C. With respect to the phosphorus component, Simpson teachesthat the same often has been included in hydrotreating catalysts toincrease catalyst acidity and thereby improve activity.

While the patents and publication discussed above disclose that the useof phosphoric acid in the preparation of hydrotreating catalystscontaining Group VIB and Group VIII metal components is beneficial tothe preparations, reported effects on catalytic activity and performancevary significantly. For example, the general statement in Simpson, U.S.Pat. No. 4,255,282 regarding use of a phosphorus component to increaseacidity and thereby improve activity, is contrary to the teaching ofColgan, U.S. Pat. No. 3,840,472 that use of phosphoric acid in improperamounts can adversely affect catalyst activity and strength.

Other patents relating to hydroconversion or hydrotreating processesdisclose various catalysts, their method of preparation as well as theiruse in such processes. For example, Simpson et al., U.S. Pat. No.4,500,424 and its divisional patent, U.S. Pat. No. 4,818,743 aredirected to hydrocarbon conversion catalysts containing at least oneGroup VIB metal component, at least one Group VIII metal component, anda phosphorus component on a porous refractory oxide having a defined andnarrow pore size distribution. The catalyst is said to be useful forpromoting various hydrocarbon conversion reactions, particularlyhydrodesulfurization. Similarly, Nelson et al., U.S. Pat. No. 5,545,602is directed to hydrotreatment of heavy hydrocarbons to increase contentof components boiling below 1000° F. by contact with Group VIIInon-noble metal oxide and Group VIB metal oxide on alumina havingspecific and defined surface area and pore size distribution. Thispatent also teaches, at column 9, lines 36-37, to avoid addingphosphorous containing components during catalyst preparation because“Presence of phosphorous undesirably contributes to sediment formation.”In furtherance of this teaching it is suggested, at lines 54-57, thatimpregnating solutions may be stabilized with H₂O₂ so that solutionsstabilized with H₃PO₄ not be used. See also Dai et al., U.S. Pat. Nos.5,397,956 and 5,498,586 similarly directed to defined carrier propertiesfor improved hydroconversion catalysts.

Plantenga, et al., U.S. Pat. No. 6,566,296 relates to a process forpreparing a catalyst composition wherein at least one Group VIIInon-noble metal component and at least two Group VIB metal componentsare combined and reacted in the presence of a protic liquid, e.g.,water, and an organic oxygen-containing additive, e.g.,diethyleneglycol, is added. The resulting composition is isolated anddried, and, while calcining is an option that results in removal of theoxygen-containing additive, the examples are directed to dried andcrushed catalyst particles.

Notwithstanding the diverse teachings of the above patents andpublication in respect of the preparation of hydrotreating catalysts,there is a continuing need for development of improved catalysts.

SUMMARY OF THE INVENTION

It has been discovered that stable catalyst carrier impregnatingsolutions can be prepared using a component of a Group VIB metal, e.g.,molybdenum, at high concentration, a component of a Group VIII metal,e.g., nickel, at low concentration, and a phosphorous component, e.g.,phosphoric acid, at low concentration, provided that the Group VIIImetal is in a substantially water-insoluble form and a particularsequence of addition of the components is followed, even when asubstantially water-insoluble form of the Group VIB component is used.The resulting stabilized impregnating solution can be supplemented withadditional Group VIII metal in water-soluble form to achieve increasedlevels of such metal in the final catalyst. Furthermore, it has beendiscovered that uncalcined catalyst carriers impregnated with the stablesolution and subsequently shaped, dried and calcined, have unexpectedlyimproved performance when used in hydrocarbon conversion processes,especially in the hydrodesulfurization, hydrodemetallation,hydrodenitrification and hydroconversion of heavy hydrocarbons. Thecatalyst is particularly useful in hydroconversion processes using heavyhydrocarbon feedstocks in which high conversion can be achieved atreduced levels of sediment, especially in comparison to standardcommercial catalysts.

Accordingly, one aspect of the invention is a stabilized composition foruse in impregnating catalyst carriers comprising: (A) water; (B)catalytically active metals being in the form of and comprising: (1) atleast one component providing at least one metal from Group VIB of theperiodic table; and (2) at least one component providing at least onemetal from Group VIII of the periodic table; wherein (i) the Group VIIImetal is provided by a substantially water insoluble component; (ii) themolar ratio of the Group VIII metal to Group VIB metal is about 0.05 toabout 0.45, provided that the amount of the Group VIII metal issufficient to promote the catalytic effect of the Group VIB metal; (iii)the concentration of the Group VIB metal, expressed as the oxide, is atleast about 3 to about 50 weight percent based on the weight of thecomposition; and (C) at least one substantially water-soluble,phosphorous-containing acidic component in an amount sufficient toprovide a phosphorous to Group VIB metal molar ratio of about 0.05 toless than about 0.25.

Another aspect of the invention is a composition for use in preparing acatalytically active solid, the composition comprising: (A) water in aquantity sufficient to provide a shaped foraminous catalyst mixture; (B)catalytically active metals useful in chemically refining hydrocarbons,the metals in the form of at least one component providing at least onemetal from Group VIB of the periodic table and at least one componentproviding at least one metal from Group VIII of the periodic table,wherein the molar ratio of the Group VIII metal to Group VIB metal isabout 0.05 to about 0.45, and wherein the Group VIII metal component isprovided by a substantially water insoluble component; and (C) at leastone substantially water-soluble phosphorous-containing acidic componentin an amount sufficient to provide a phosphorous to Group VIB molarratio of about 0.05 to about 0.25; and (D) at least one uncalcinedforaminous catalyst carrier.

A further aspect of the invention is a method of preparing stabilizedaqueous compositions for use in impregnating catalyst carriers toproduce catalyst precursors and catalysts comprising adding to asuitable quantity of water: (A) at least one substantially waterinsoluble Group VIII metal component; and (B) at least one substantiallywater soluble, phosphorous-containing acidic component in an amountinsufficient to cause dissolution of the Group VIII metal component soas to produce a slurry, and combining the slurry with: (C) at least oneGroup VIB metal component; and (D) mixing the combination of (A), (B)and (C) and heating the mixture, for a time and to a temperaturesufficient for (A), (B) and (C) to form a solution; and (E) adding anadditional amount of water, if required, to obtain solutionconcentrations of the at least one Group VIII metal, the at least oneGroup VIB metal and phosphorous useful for impregnating the carriers;wherein Group VIB and Group VIII refer to Groups of the periodic tableof the elements.

A still further aspect of the invention is a catalyst prepared byimpregnation of a catalyst carrier with a stabilized aqueous compositionas described above and including the step of separating the volatileportion of the solution from the impregnated uncalcined carrier toobtain a dried composition having a desired moisture content andcalcining the dried composition.

Another aspect of the invention is a catalyst useful in chemicallyrefining hydrocarbons, the catalyst comprising at least onecatalytically active metal from Group VIB of the periodic table, atleast one catalytically active metal from Group VIII of the periodictable, and phosphorous, wherein the metals and phosphorous are carriedon a foraminous carrier, wherein the pore mode is typically about 40 toabout 90 Å, wherein the loss in weight on ignition at 1000° F. to 1200°F. of the catalyst is less than about 5 wt. based on the weight of thecatalyst, and wherein the ASI ratio is greater than about 0.75 to about2.0. The catalyst is particularly useful in hydroconversion processesusing heavy hydrocarbon feedstocks in which high conversion can beachieved at reduced levels of sediment, especially in comparison tostandard commercial catalysts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the performance of catalysts prepared according tothe invention in terms of sulfur conversion.

FIG. 2 illustrates the performance of catalysts prepared according tothe invention in terms of microcarbon residue conversion.

FIG. 3 illustrates the performance of catalysts prepared according tothe invention in terms of sediment vs. 1000 F+ conversion.

DETAILED DESCRIPTION OF THE INVENTION

For purposes of the present specification, the following words andphrases shall have the following meanings:

The word “component” with regard to the metals and phosphorous of theimpregnating solution and catalyst refers to any compound or complex,including a salt, oxide, sulfide, or any intermediate form between oxideand sulfide of the metal or phosphorous in question.

All references herein to elements or metals belong to a certain Grouprefer to the Periodic Table of the Elements and Hawley's CondensedChemical Dictionary, 13^(th) Edition. Also, any references to the Groupor Groups shall be to the Group or Groups as reflected in this PeriodicTable of Elements using the CAS system for numbering groups.

For purposes of the present invention, the terms “pre-impregnated” and“post-impregnated” (and the equivalent terms, “pre-calcined” and“post-calcined”) are used in connection with the catalysts of thepresent invention.

“Pre-impregnated” catalyst refers to a catalyst in which themetals-containing solution or solutions are added before the foraminouscatalyst carrier is calcined. The metals-containing solution orsolutions can be added prior to or after shaping of the catalystparticle, but the important aspect is that the metals-containingsolution or solutions be added prior to the carrier material beingcalcined. However there are significant advantages to be gained byshaping of the uncalcined carrier after impregnation (contact) with theaqueous solution of the present invention. These advantages are observedin the form of more desirable distribution of the metals throughout thecarrier in the final catalyst. Thus, a “pre-impregnated” catalyst can bemade as follows:

Uncalcined pseudoboehmite alumina powder is thoroughly mixed with water,or optionally with a dilute aqueous solution of nitric acid, and themixture is combined with a suitable quantity of a stable metals solutionof the present invention as described in detail hereinbelow. Forexample, such solution typically contains molybdenum, nickel andphosphorus, plus an optional additional quantity of Group VIII metalssolution, if required in order to provide the desired amount of metalson the finished catalyst. Note that the identity of the Group VIII metalcomponent employed to achieve the optional additional quantity of theGroup VIII metal is typically selected to be water-soluble under thetemperature conditions encountered.

The metal-containing mixture, typically containing about 50 to about 65weight percent moisture, is shaped into catalyst particles having adesired size, preferably by extrusion. The formed catalyst particles aredried at a temperature of about 110 to about 150° C., and then calcinedat a temperature of about 500 to about 750° C. for about one to abouttwo hours.

“Post-impregnated” catalyst refers to a catalyst in which themetals-containing solution or solutions are added after the foraminouscatalyst carrier is calcined. The foraminous catalyst carrier can becalcined before or after shaping of the catalyst particle, but theimportant aspect is that the metals-containing solution or solutions beadded after the carrier material is calcined. Thus, a “post-impregnated”catalyst can be made as follows:

Uncalcined pseudoboehmite alumina powder is thoroughly mixed with water,or optionally with a dilute aqueous solution of nitric acid, and thealumina mixture, containing about 50 to 65 weight percent moisture, isthen formed into catalyst particles having a desired size and shape,preferably by extrusion. The formed particles are dried at a temperatureof about 110 to about 150° C., and then calcined at a temperature ofabout 400 to about 750° C. for about one to two hours. The dried andcalcined particles are contacted with a suitable quantity of a stablemetals solution of the present invention as described in detailhereinbelow. For example, such solution typically contains molybdenum,nickel and phosphorus, plus an optional additional quantity of GroupVIII metals solution, if required, in order to provide the desiredamount of metals on the finished catalyst, while substantially anduniformly filling the pores. After a suitable contact time, the formedcatalyst particles are dried at a temperature of about 110 to about 150°C., and then calcined at a temperature of about 400 to about 750° C. forabout one to about two hours.

It will be observed that a significant distinction between apre-impregnated catalyst and a post-impregnated catalyst is that thepost-impregnated catalyst undergoes two calcining steps; typically oneconsisting essentially of the foraminous carrier and the second in whichthe carrier has been “loaded” with the catalytically active metalcomponents including the phosphorous component. In contrast, thepre-impregnated catalyst undergoes one calcining step, as described.

“Substantially” as applied to any criteria, such as a property,characteristic or variable, means to meet the stated criteria in suchmeasure such that one skilled in the art would understand that thebenefit to be achieved or condition desired is met. Further, morespecific definitions may be found herein as the term applies to specificfeatures of the invention.

Suitable catalytically active elements or metals from Group VIII of theperiodic table present in components of the invention may include Fe,Co, Ni, Pd, Pt and the like and mixtures thereof. Of these, the mostpreferable are Co and Ni. Suitable Group VIB elements or metals includeCr, Mo, W, and mixtures thereof; most preferred are Mo and W. Preferredcombinations of metal components comprise e.g., nickel and molybdenum,cobalt and molybdenum, tungsten and nickel or cobalt, molybdenum and acombination of cobalt and nickel, tungsten and a combination of nickeland cobalt, a combination of molybdenum and chromium and nickel, etc;the combination of molybdenum and nickel is particularly preferred.

The overall process for preparing the stable impregnating solution ofthe invention and some of the advantages accruing from the process canbe described as follows:

An amount of a substantially water-insoluble Group VIII metal componentis added to water to form a slurry. The amount of the Group VIII metalcomponent is low relative to the amount of the Group VIB metal componentthat will be added in a subsequent step. The specific amount of thesubstantially water-insoluble Group VIII metal component can becharacterized by the molar ratio of the Group VIII metal to the GroupVIB metal in the final impregnating solution; typically, the molar ratiois from about 0.05 to about 0.45; other suitable ranges of this variableand others are described below.

To the aqueous slurry of the substantially water-insoluble Group VIIImetal component just described, is added an aqueous solution of awater-soluble, phosphorus-containing acidic component. The amount ofthis acidic phosphorus component is low relative to the amount of theGroup VIB metal component that will be added in a subsequent step, andis at a level insufficient to cause the Group VIII metal component tobecome substantially soluble at this stage of the process, although itis believed that the components added in these steps 1 and 2 undergoreaction. In any event, a slurry of the components is maintained at thisstage. The specific amount of the water-soluble, phosphorus-containingacidic component can be characterized by the molar ratio of phosphorusto the Group VIB metal in the final impregnating solution; typicallythis molar ratio is from about 0.05 to less than 0.25.

To the aqueous slurry present at the end of step 2, is added the GroupVIB metal component. The resulting slurry mixture is heated for a timeand to a temperature sufficient for the Group VIB metal component toreact with the aqueous slurry produced by the substantiallywater-insoluble Group VIII metal component and the water-soluble,phosphorus-containing acidic component, and to form a solution.Generally, mixing and heating may be carried out over a period of about1 to about 8 hours and at a temperature of about 160 to about 200° F.

The concentration of the Group VIB metal component in the impregnatingsolution composition can be quite high, up to about 50 weight percent,expressed as the oxide, and based on the total weight of theimpregnating solution composition. It should be obvious to those skilledin the art that more dilute solutions, useful for particularapplications, can be obtained by diluting the concentrated compositionwith a suitable amount of water.

Additional Group VIII metal, in the form of a substantiallywater-soluble Group VIII metal component, can be added to thecompositions in step 4 as required to give the desired level of GroupVIII metal component and the desired ratio of Group VIII metal componentto Group VIB metal component in the finished catalyst. The ratio ofGroup VIII metal component to Group VIB metal component can thus bevaried from about 0.05 to about 1.0.

The catalyst impregnating compositions produced by the method described,allow for high concentrations of the Group VIB metal component at lowrelative concentrations of both the phosphorus and Group VIII metalcomponents. The low relative concentration of the phosphorus componentcan be advantageous for the preparation of catalysts that can benefitfrom or tolerate a low level of phosphorus. Additionally, this catalystimpregnating solution is surprisingly stable, i.e., it can be stored forextended periods as a solution without the formation of precipitates.

The low relative concentration of the Group VIII metal component isadvantageous for several reasons. First, the compositions allow for thepreparation of catalysts with a wide range of ratios of Group VIII metalcomponent to Group VIB metal component. Second, a substantial amount ofthe Group VIII metal component required for the finished catalyst can beadded in the form of a substantially water-soluble Group VIII metalcomponent that might otherwise be difficult to solubilize in thepresence of a large amount of Group VIB metal component unless asignificantly larger amount of the acidic phosphorous component wasused. These substantially water-soluble Group VIII metal components,especially the salts of mineral acids (e.g., nitrates), can be morecost-effective than the substantially water-insoluble Group VIII metalcomponent salts (e.g., carbonates). Third, as will be described andexemplified, the impregnating solution of the present invention can beused to produce a hydroconversion catalyst having excellent performancecharacteristics.

Suitable Group VIII metal components for use in the invention which arecharacterized herein as substantially insoluble in water include thecitrates, oxalates, carbonates, hydroxy-carbonates, hydroxides,phosphates, phosphides, sulfides, aluminates, molybdates, tungstates,oxides, or mixtures thereof. Oxalates, citrates, carbonates,hydroxy-carbonates, hydroxides, phosphates, molybdates, tungstates,oxides, or mixtures thereof are preferred; most preferred arehydroxy-carbonates and carbonates. Generally, the molar ratio betweenthe hydroxy groups and the carbonate groups in the hydroxy-carbonate isin the range of about 0-4; preferably about 0-2; more preferably about0-1; and most preferably about 0.1-0.8. In particular, suitablesubstantially water insoluble components providing a Group VIII metalare the carbonates and hydroxides of nickel and cobalt.

Suitable substantially water-soluble components providing a Group VIIImetal for use in the invention include salts, such as nitrates, hydratednitrates, chlorides, hydrated chlorides, sulfates, hydrated sulfates,formates, acetates, or hypophosphite. Suitable substantiallywater-soluble nickel and cobalt components include nitrates, sulfates,acetates, chlorides, formates or mixtures thereof, as well as nickelhypophosphite. Suitable water-soluble iron components include ironacetate, chloride, formate, nitrate, sulfate or mixtures thereof. Inparticular, substantially water-soluble components are salts such asnickel and cobalt nitrates, sulfates, and acetates.

An indicator of the relative solubility of the substantially insolubleand soluble components, can be found by comparing nickel carbonate tonickel nitrate or nickel sulfate. As reported in the CRC Handbook ofChemistry and Physics, 69^(th) Ed., 1988-9 (R. C. Weast, Ed., CRCPress), nickel carbonate has a solubility of about 0.009 g/100 mL ofwater whereas nickel nitrate has a solubility of about 239 g/100 mL andnickel sulfate a solubility of about 29-76 g/100 mL, depending on thewater of hydration of the particular salt. Furthermore, the solubilityof the sulfate salts increases to about 87-476 g/100 mL in hot water.Consequently, one skilled in the art will understand the reference to“substantial” with regard to water solubility of these components.Alternatively, for purposes of the present invention, the aqueoussolubility of a substantially water insoluble Group VIII metal componentis generally less than 0.05 moles/100 mL (at 18° C.); conversely, thesolubility of a substantially water-soluble component is greater than0.05 moles/100 mL, e.g., greater than about 0.10 moles/100 mL (at 18°C.).

Suitable components providing a Group VIB metal include bothsubstantially water-soluble and substantially water insolublecomponents. Suitable substantially water-soluble Group VIB metalcomponents include Group VIB metal salts such as ammonium or alkalimetal monomolybdates and tungstates as well as water-solubleisopoly-compounds of molybdenum and tungsten, such as metatungstic acid,or water-soluble heteropoly compounds of molybdenum or tungstencomprising further, e.g., P, Si, Ni, or Co or combinations thereof.Suitable substantially water-soluble isopoly- and heteropoly compoundsare given in Molybdenum Chemicals, Chemical data series, BulletinCdb-14, February 1969 and in Molybdenum Chemicals, Chemical data series,Bulletin Cdb-12a-revised, November 1969. Suitable substantiallywater-soluble chromium compounds include chromates, isopolychromates andammonium chromium sulfate. Suitable Group VIB metal components that aresubstantially water insoluble, e.g., having a low solubility in water,include di- and trioxides, carbides, nitrides, aluminium salts, acids,sulfides, or mixtures thereof. Preferred substantially insoluble GroupVIB metal components are di- and trioxides, acids, and mixtures thereof.Suitable molybdenum components include molybdenum di- and trioxide,molybdenum sulfide, molybdenum carbide, molybdenum nitride, aluminiummolybdate, molybdic acids (e.g. H₂MoO₄), ammonium phosphomolybdate, ormixtures thereof; molybdic acid and molybdenum di- and trioxide arepreferred. Suitable substantially insoluble tungsten components includetungsten di- and trioxide, tungsten sulfide (WS₂ and WS₃), tungstencarbide, orthotungstic acid (H₂WO₄·H₂O), tungsten nitride, aluminiumtungstate (also meta- or polytungstate), ammonium phosphotungstate, ormixtures thereof; orthotungstic acid and tungsten di- and trioxide arepreferred. Most preferred is molybdenum trioxide, MoO₃. For purposes ofthe present invention, the aqueous solubility of a substantially waterinsoluble Group VIB metal component is generally less than 0.05moles/100 mL (at 18° C.); conversely, the solubility of a substantiallywater-soluble component is greater than 0.05 moles/100 mL, e.g., greaterthan about 0.10 moles/100 mL., the oxides such as molybdenum trioxide,molybdenum blue, also identified as molybdenum pentoxide, tungsticoxide, etc.; the acids, e.g., molybdic, tungstic and chromic acids;metal salts such as the ammonium, alkali and alkaline earth metals,e.g., ammonium heptamolybdate, ammonium phosphomolybdate, ammoniumparatungstate; and the complex salts of Group VIB and Group VIII metalssuch as complex cobalt and nickel phosphomolybdates.

The phosphorous-containing acidic component is substantially watersoluble, preferably a water soluble, acidic component that may be anoxygenated inorganic phosphorus-containing acid such as phosphoric acidalthough any one or more of the phosphoric acids may be used, includingorthophosphoric acid, metaphosphoric acid, pyrophosphoric acid,triphosphoric acid and tetraphosphoric acid and mixtures thereof. Forthe purposes of the invention, substantial phosphorous water solubilitymeans sufficient solubility to react with the substantiallywater-insoluble Group VIII metal component. Additionally, a soluble saltof phosphoric acid, such as the ammonium phosphates may also be used.Phosphoric acid may be added to the solution in liquid or solid form. Apreferred compound is orthophosphoric acid (H₃PO₄) in a highlyconcentrated aqueous solution, although any suitable form of phosphoricacid or precursor thereof, e.g., phosphorus pentoxide (P₂O₅) may beutilized. Naturally, concentrated acid may be appropriately diluted foruse or an appropriate form of dilute acid may be used directly.

Should it be desired to supplement the composition with an acid, e.g.,in order to adjust the pH, other suitable, water-soluble acids can beused, such as a hydroxy monocarboxylic acid, a polyhydroxymonocarboxylic acid, a hydroxy polycarboxylic acid, a polyhydroxypolycarboxylic acid, a monocarboxylic acid, etc.

The catalyst composition typically comprises about 5 to about 35 wt. %of the total of Group VIB and Group VIII metal components, calculated asoxides based on the total weight of the catalyst composition;preferably, about 8 to about 30 wt. %, more preferably about 10 to about25 wt. %. The amount of Group VIB metals and Group VIII metals can bedetermined using atomic absorption spectrometry (AAS),inductively-coupled plasmaspectrometer (ICP) analysis and/or x-rayfluorescence (XRF).

Examples of suitable foraminous carrier materials include silica, silicagel, silica-alumina, alumina, titania, titania-alumina, zirconia, boria,terrana, kaolin, magnesium silicate, magnesium carbonate, magnesiumoxide, aluminum oxide, precipitated aluminum oxide, activated alumina,bauxite, kieselguhr, pumice, natural clays, synthetic clays, cationicclays or anionic clays such as saponite, bentonite, kaolin, sepiolite orhydrotalcite, and mixtures thereof. Preferred foraminous carriercomponents are silica, silica-alumina, alumina, titania,titania-alumina, zirconia, bentonite, boria, and mixtures thereof;silica, silica-alumina, and alumina are especially preferred. Aluminacan be prepared, e.g., by converting an alumina precursor such asboehmite, into a preferred carrier material gamma-alumina.

Preferably, the catalyst composition following impregnation, drying andcalcinations, i.e., wherein the metal components and phosphorus arepresent as oxides, and, preferably, prior to a sulfidation step, if any,has a BET surface area typically about 225 m²/g to about 500 m²/g;preferably about 250 m²/g to about 400 m²/g; more preferably about 250m²/g to about 350 m²/g; most preferably about 250 m²/g to about 330m²/g; as measured using either of two tests according to the Brunauer,Emmett and Teller (BET) method: ASTM D3663, a multipoint test or ASTMD4567, a single point test. The pore mode diameter by volume (dV/dD max)of the calcined catalyst composition, i.e., metals present as oxides, istypically about 40 to about 90 Å; preferably about 45 to about 80 Å (bythe mercury porosimetry method, ASTM D4284 Standard Test Method forDetermining Pore Volume Distribution of Catalysts by Mercury IntrusionPorosimetry; using a contact angle of 130° and surface tension of 484dynes/cm). The total pore volume, also referred to as the totalintrusion volume (TIV), of the calcined catalyst composition istypically at least about 0.50 cc/g; preferably about 0.50 to about 2cc/g; more preferably about 0.7-1.5 cc/g, as determined by mercuryporosimetry (also using ASTM D4284).

The term “agglomerate” refers to a product that combines particles thatare held together by a variety of physical-chemical forces and the term“shaping” and grammatical variations thereof refers to the act offorming agglomerates. More specifically, each agglomerate is composed ofa plurality of contiguous, constituent primary particles, preferablyjoined and connected at their points of contact. Thus, the agglomeratesparticles typically exhibit a higher macropore content than theconstituent primary particles from which they are made because of theinterparticle voids between the constituent composite particles.

Agglomeration of the foraminous carrier, e.g., alumina, composite iscarried out in accordance with methods well known to the art, and, inparticular, by such methods as pelletizing, extrusion, shaping intobeads in a rotating coating drum, and the like. The modulizing techniquewhereby composite particles having a diameter of not greater than about0.1 mm are agglomerated to particles with a diameter of at least about 1mm by means of a granulation liquid may also be employed. As is known tothose skilled in the art, agglomeration may optionally be carried out inthe presence of additional amorphous or crystalline binders, andpore-forming agents may be added to the mixture to be agglomerated.Conventional binders include other forms of alumina, silica,silica-alumina, clays, zirconia, silica-zirconia, magnesia andsilica-boria. Conventional pore-forming agents which can be used inparticular, include wood flour, wood charcoal, cellulose, starches,naphthalene and, in general, all organic compounds capable of beingremoved by calcination. The addition of pore forming agents, however, isnot necessary or desirable.

The catalyst composition may have different shapes selected for theirsuitability for the process and/or equipment in which they are to beused. For example, if the catalyst composition is to be used inslurry-type reactors, fluidized beds, moving beds, or expanded beds,generally spray-drying or beading is applied. For fixed bed orebullating bed applications, generally the catalyst composition isextruded, pelletized and/or beaded. In the latter case, at any stageprior to or during the shaping step, any additives, which areconventionally used to facilitate shaping, can be added. These additivesmay comprise aluminium stearate, surfactants, graphite, starch, methylcellulose, bentonite, polyethylene glycols, polyethylene oxides ormixtures thereof. Further, as discussed elsewhere, when alumina is usedas the carrier, nitric acid is sometimes added prior to the shaping stepfor the purpose of, e.g., increasing the mechanical strength of theagglomerates. In the present invention the shaping step is carried outin the presence of water. For extrusion and beading, the amount of waterin the shaping mixture, expressed as LOI, preferably is in the range of20-80%. If required by the shaping operation, additional water can beadded or, if the amount of water is too high, it can be reduced by,e.g., solid-liquid separation via, e.g., filtration, decantation, orevaporation. It is within the scope of the skilled person to control theamount of water appropriately.

Suitable shapes include powders, spheres, cylinders, rings, andsymmetric or asymmetric polylobal forms, for instance tri- andquadrulobal. Particles resulting from extrusion, beading or pelletingusually have a diameter in the range of about 0.2 to about 10 mm, andlengths in the range of about 0.5 to about 20 mm, but deviations fromthese general ranges are possible Catalysts in the form of extrudatesare generally preferred.

The present invention is also directed to catalyst compositionsaccording to the invention wherein the metal components have beenconverted partly or wholly into their sulfides. In that case, it ispreferred for the catalyst to be essentially free from Group VIII metaldisulfides.

Calcination is generally carried out at a temperature typically about200 to about 850° C.; preferably about 350 to about 800° C.; morepreferably about 450 to about 750° C. The calcination time generallyvaries from about 0.5 to about 48 hours. The calcination may be carriedout in an inert gas such as nitrogen, or in an oxygen-containing gas,such as air or pure oxygen, and optionally in the presence of steam.Preferably, the calcination is carried out in an oxygen-containingatmosphere.

Embodiments of the present invention include:

(I) A stabilized composition adapted for use in impregnating catalystcarriers comprising: (A) water; (B) catalytically active metals being inthe form of and comprising: (1) at least one component providing atleast one metal from Group VIB of the periodic table; and (2) at leastone component providing at least one metal from Group VIII of theperiodic table; wherein (i) the Group VIII metal is provided by asubstantially water insoluble component; (ii) the molar ratio of theGroup VIII metal to Group VIB metal is about 0.05 to about 0.45,provided that the amount of the Group VIII metal is sufficient topromote the catalytic effect of the Group VIB metal; and (iii) theconcentration of the Group VIB metal, expressed as the oxide, is atleast about 3 to about 50 weight percent based on the weight of thecomposition; and (C) at least one water soluble, phosphorous-containingacidic component in an amount sufficient to provide a phosphorous toGroup VIB metal molar ratio of about 0.05 to less than about 0.25. If itis desired to prepare a low metal concentration catalyst, the stabilizedaqueous impregnating composition can have a relatively diluteconcentration of the Group VIB metal, for example, from about 3 to about6 weight percent; for example, about 3.5 to about 5.5 weight percent. Incontrast, where a higher metal content catalyst is desired, theimpregnating composition can contain about 25 to about 50 weight percentof the Group VIB metal; for example, about 26 to about 46 weightpercent; or about 28 to about 42 weight percent. Other usefulcompositions are found within the range of about 3 to about 50 weightpercent of the Group VIB metal including, for example, 7-27, 8-26, 10-24as well as concentrations in the range of about 12 to about 48 weightpercent; for example about 13 to about 40 weight percent. Useful molarratios of the Group VIII metal to Group VIB metal are about 0.05 toabout 0.40; or about 0.05 to about 0.30; for example, about 0.10 toabout 0.25. Furthermore, the molar ratio of phosphorus to Group VIBmetal can be about 0.07 to about 0.23; or about 0.08 to about 0.20; forexample, about 0.09 to about 0.18.

The impregnating solution prepared in the sequence described in detailbelow is surprisingly stable and can be stored for an extended period oftime until needed to prepare the catalyst. The composition can be stablefor periods in excess of hours, days and weeks, even periods in excessof a month or more.

Where a catalyst is desired having a higher concentration of Group VIIImetal, e.g., nickel, the aqueous impregnating solution can besupplemented with a nickel component in soluble form. In that case, thetotal amount of Group VIII metal is increased and the molar ratio ofGroup VIII metal to Group VIB metal can typically range from about 0.05to about 1.0; preferably about 0.05 to about 0.9; more preferably about0.05 to about 0.7. As will be later described, the additional, solubleGroup VIII metal component can be included in the aqueous impregnatingsolution or, preferably, added as an aqueous solution to the combinationof foraminous carrier and impregnating composition described above.

The stable aqueous impregnating solution described in (I) above can beemployed in a process for preparing the catalyst of the presentinvention as follows: A mixture is prepared using the impregnatingsolution of (I), a quantity of additional Group VIII metal component insoluble form where the catalyst is to contain a higher level of theGroup VIII metal than is available in (I) and a foraminous powder. Itshould be appreciated that alternative variations are also feasible. Forexample, the soluble Group VIII metal component could be combined with(I) to provide the total amount of such metal required and that mixturecould constitute one feed component. Alternatively, the foraminouscarrier could be combined with the soluble Group VIII metal componentand that mixture could be combined with (I) in the desired quantity.Alternative convenient arrangements will be apparent to a person skilledin the art. The just-described components are fed to a mixer, forexample, a short residence time, low energy mixer or a higher energymixing device in order to combine these components. Optionally,additional water can be included in order to obtain a “damp mix.” Such amixture is understood to have sufficient moisture to provide acomposition that is capable of holding its shape after being extruded orcompressed into the desired shape. In other words, if the mixturecontains an excessive amount of water it will be resemble a slurry andif too little water, it will tend to crumble and be incapable of holdingits shape. Optionally, and particularly where a low energy mixing deviceis used, the additional water added to the mixer can contain a smallquantity of nitric acid. Typically, a 75 weight percent nitric acidsolution is added at a rate of about 5 to about 6 weight percent basedon the weight of alumina. The amount to be added is based on thequantity of foraminous carrier powder fed to the mixer rather than thepH of the mixture and, when a high energy mixer is used, addition ofnitric acid may not be necessary. When circumstances call for its use asdescribed, it has been found that the addition of the acid is beneficialto the formation of a desirable pore structure in the final catalyst.The mixture exiting from the mixer is fed to a device for shaping themixture into the desired catalyst form. Preferably such shaping isaccomplished in an extruder although other forming methods can beemployed, e.g., based on compression.

This embodiment of the invention can be accomplished using a compositionbased on (I) above and further generally described as follows:

(II) A composition for use in preparing a catalytically active soliduseful in chemically refining hydrocarbons, the composition comprising:(A) water in a quantity sufficient to provide a shaped foraminouscatalyst mixture; (B) catalytically active metals useful in chemicallyrefining hydrocarbons, the metals in the form of at least one componentproviding at least one metal from Group VIB of the periodic table and atleast one component providing at least one metal from Group VIII of theperiodic table, wherein the molar ratio of the Group VIII metal to GroupVIB metal is about 0.05 to about 0.45, and wherein the Group VIII metalcomponent is provided by a substantially water insoluble component; and(C) at least one water soluble phosphorous-containing acidic componentin an amount sufficient to provide a phosphorous to Group VIB molarratio of about 0.05 to less than about 0.25; and (D) at least oneforaminous catalyst carrier. The compositional variations describedabove with regard to (I) apply, as well, to (II) and will not berepeated.

The method used to prepare the aqueous composition of (I) above isunique in that it results in a stable composition, as described, eventhough the amount of phosphorous-containing acidic component, e.g.,phosphoric acid, is insufficient to effect dissolution of thesubstantially water insoluble Group VIII metal component when the twoare combined. The method, representing another embodiment of theinvention, can be generally described as follows:

(III) A method of preparing stabilized aqueous compositions for use inimpregnating catalyst carriers to produce catalyst precursors andcatalysts useful in chemically refining hydrocarbons, comprising addingto a suitable quantity of water: (A) at least one substantially waterinsoluble Group VIII metal component to produce a slurry; (B) at leastone substantially water soluble, phosphorous-containing acidic componentin an amount insufficient to cause dissolution of the Group VIII metalcomponent so as to produce a slurry and combining the slurry with; (C)at least one Group VIB metal component; (D) mixing the combination of(A), (B) and (C) and, heating the mixture, for a time and to atemperature sufficient for (A), (B) and (C) to form a solution; and (E)adding an additional amount of water, if required, to obtain solutionconcentrations of the at least one Group VIII metal, the at least oneGroup VIB metal and phosphorous useful for impregnating the carriers;wherein Group VIB and Group VIII refer to Groups of the periodic tableof the elements. Useful amounts, concentrations and ratios of thecomponents are as further described in (I) above. Typically, mixing andheating is carried out over a period of about 0.5 to about 16 hours;preferably about 1 to about 8 hours; more preferably about 1 to about 4hours; at a temperature typically about 150 to about 220° F.; preferablyabout 160 to about 200° F.; more preferably about 180 to about 190° F.

It can be seen that a catalyst prepared as described herein correspondsto a pre-impregnated catalyst as defined above. Although differences inthe methods and compositions used to prepare such catalysts may beconsidered small compared to those described in the art, the catalystresulting from these changes performs significantly better inhydrocarbon conversion processes than catalysts prepared according toprior art methods. Such advantages could not have been foreseen.Furthermore, the catalysts of the present invention are characterized byproperties that similarly distinguish them from comparable catalystsprepared by standard methods. In particular, the catalysts arecharacterized by the Active Site Index, believed to correspond to theratio of promoted to unpromoted Group VIB metal sites of the catalyst;in a preferred embodiment the Group VIB metal is molybdenum and theGroup VIII metal is nickel or cobalt, more preferably nickel. The testmethod, based on the work by N.Y. Topsoe and H. Topsoe, J. Catalysis(1983), 84(2), 386-401, is as follows:

A sample of the catalyst is ground to −100 mesh, purged under vacuumovernight, then under nitrogen for one hour, and heated under 2 vol. %H₂S/98 vol. % H₂ for two hours at 150° C., two hours at 250° C. andthree hours at 380° C., then nitrogen overnight at 380° C. The sample iscooled to room temperature, purged under vacuum for one hour and NO isflowed over the sample at room temperature for two hours. The sample isflushed with nitrogen for one hour, vacuum for one hour and nitrogen isintroduced to fill the sample chamber. The sample chamber is sealed,then moved to an inert atmosphere glove box for infrared (IR) analysis.The Active Site Index (ASI) is calculated by dividing the height of thepeak at about 1852 cm⁻¹ (believed to correspond to the promotedmolybdenum sites) by the height of the peak at about 1716 cm⁻¹ (believedto correspond to the unpromoted molybdenum sites).

A catalyst can be prepared under controlled conditions in a laboratoryin order to evaluate the effect of the impregnating solution preparationmethod, the catalyst impregnation method, as well as other catalystpreparation variables on ASI. In a standard procedure, a catalystcarrier is thoroughly mixed with water, or optionally with a diluteaqueous solution of nitric acid. The mixture is combined with a suitablequantity of a metals-impregnating solution or solutions containing atleast one Group VIB and one Group VIII metal prepared according to thepresent invention in order to provide the desired level of the metals onthe finished catalyst. Alternatively, for comparative purposes, theimpregnating solution or solutions can be prepared according to standardmethods and/or the impregnation can be carried out using apost-calcining procedure, as defined above. The metal-containingforaminous mixture is then shaped into catalyst agglomerate particleshaving a desired size, for example by extrusion.

The shaped catalyst particles are dried at a temperature of about 250°F. for at least four hours, and then calcined at a temperature of atleast 1250° F. for at least one hour, such that the finished catalystparticles have less than about 1% total volatiles as measured at 1000°F. The catalyst can then be tested according to the ASI proceduredescribed above.

The catalyst of the present invention is characterized by high values ofASI compared to typical pre-impregnated catalyst used in hydroconversionprocesses. Such prior art catalysts typically have ASI values less thanabout 0.7 whereas catalysts prepared according to the present inventionhave values that are greater than 0.7, typically greater than about 0.75to about 2.0; generally at least about 0.80 to about 1.5; preferablyabout 0.85 to about 1.2; values greater than about 0.90 have beenobserved. Furthermore, the catalyst of the present invention has beenexamined in cross-section and the metals and phosphorous distributionacross the particle has been measured and compared to a standard,commercial catalyst, e.g., corresponding to a catalyst of the typedisclosed in U.S. Pat. No. 5,192,734. In a sample of the catalyst of thepresent invention based on molybdenum, nickel and phosphorous, themolybdenum and nickel distributions across the catalyst pellet tend tobe more uniform than in a prior art catalyst; with the molybdenumconcentration tending to be, perhaps, slightly greater at the center ofthe pellets. The improved ASI values may reflect the more uniformdistribution of molybdenum and nickel.

(IV) A further embodiment of the invention comprises a pre-impregnated,calcined catalyst useful in chemically refining hydrocarbons, thecatalyst comprising at least one catalytically active metal componentfrom Group VIB of the periodic table, at least one catalytically activemetal component from Group VIII of the periodic table, and a phosphorouscomponent, wherein the metals and phosphorous are carried on aforaminous carrier, the pore mode is typically about 40 to about 90 Å,wherein the loss in weight on ignition (LOI) at 1000° F. to 1200° F. ofsaid catalyst is less than about 5 wt. % based on the weight of thecatalyst, and the ASI ratio is greater than about 0.75 to about 2.0.

In general, the catalyst carrier may be impregnated with the stableaqueous solutions containing the catalytically active components and thephosphorous component by alternative methods provided that a previouslycalcined catalyst carrier is not employed. In one method the catalystcarrier is slurried with the catalytically active aqueous solution andheated at around 180° F. for about 2 to about 3 hours. The impregnated,unshaped carrier is filtered, dried and the moisture adjusted to theproper degree. The filtered material is shaped, e.g., extruded, and thencalcined. In a variation of this technique, the solution and carrier arecontacted in the absence of heat, but a longer contact time is requiredto achieve suitable impregnation. In another method, the catalystcarrier to be impregnated is contacted with the stable solution for asufficient time to uniformly fill the carrier pores. In this methodenough catalytically active stable solution is added to obtain a uniformwetted or damp powder. After the requisite contact time wetted carriercomposition is shaped, e.g., extruded, dried and then calcined. This isa particularly preferred method in that no filtering step or dryingtechnique is needed after impregnation, since the appropriate moisturecontent for extrusion is obtained by the use of the catalytically activestable solution. Alternatively, the foraminous carrier is allowed tosoak in the solution containing the catalytically active elements for atotal of period of time, e.g., about 1 to about 24 hours, and theimpregnated carrier is then separated from the solution by, e.g.,filtration, dried and calcined.

As described above, after the impregnating solution and carrier,preferably alumina, are contacted and shaped, preferably by extrusion,the shaped particles are dried and then calcined. Therefore, theresulting catalyst particles prepared according to the methods of thepresent invention have preferably been calcined only once.

The catalysts prepared by the methods described herein have thefollowing characteristics:

-   -   (a) Group VIB to Group VIII molar ratio typically about 20:1 to        about 1:1; preferably about 5:1 to about 1:1; more preferably        about 3:1 to about 1:1.    -   (b) Group VIB to Phosphorus molar ratio typically about 50:1 to        about 2:1; preferably about 30:1 to about 4:1; more preferably        about 25:1 to about 6:1.    -   (c) Group VIB metals level, expressed as the oxide (e.g., MoO₃),        typically about 5.0 to about 25.0 wt. %; preferably about 7.0 to        about 20.0 wt. %; more preferably about 10.0 to about 17.0 wt.        %.    -   (d) Group VIII metals level, expressed as the oxide (e.g., NiO),        typically about 0.5 to about 10.0 wt. %; preferably about 1.5 to        about 8.0 wt. %; more preferably about 3.0 to about 6.0 wt. %;    -   (e) Phosphorus level, expressed as the oxide (P₂O₅), typically        about 0.2 to about 2.0 wt. %; preferably about 0.2 to about 1.5        wt. %; more preferably about 0.2 to about 1.0 wt. %; and    -   (f) Loss on ignition (LOI), measured at either 1000° F. or        1200° F. typically less than about 5 wt. %; preferably less than        about 3 wt. %; more preferably less than about 2 wt. %.

Additionally, the physical characteristics of the finished catalystinclude the following properties:

-   -   (a) surface area (SA) typically about 225 to about 500 m²/g;        preferably about 250 to about 400 m²/g; more preferably about        250 to about 350 m²/g; most preferably about 250 m²/g to about        330 m²/g;    -   (b) total intrusion volume (TIV) is at least about 0.50 cc/g;        preferably about 0.50 cc/g; more preferably about 0.7 to about        1.5 cc/g; and    -   (c) pore mode typically about 40 to about 90 Å; preferably about        45 to about 80 Å.

(V) Furthermore, the catalysts according to the invention areparticularly useful in hydrocarbon conversion processes comprisingcontacting a hydrocarbon feedstock with a particulate catalyst underconditions of elevated temperature and elevated pressure with hydrogen,wherein the catalyst is made according to the present invention. Asgenerally described, such catalysts comprise at least one catalyticallyactive metal from Group VIB of the periodic table, at least onecatalytically active metal from Group VIII of the periodic table, andphosphorous, wherein the metals and phosphorous are carried on aforaminous carrier, the pore mode is typically about 40 to about 90 Å,and wherein the ASI ratio is greater than about 0.75 to about 2.0.

Catalysts prepared according to the present invention can be used invirtually all hydroprocessing processes to treat a plurality of feedsunder wide-ranging reaction conditions, generally, for example, attemperatures in the range of about 200° to about 500° C., hydrogenpressures in the range of about 5 to 300 bar, and liquid hourly spacevelocities (LHSV) in the range of about 0.05 to 10 h⁻¹. The term“hydroprocessing” can encompass various processes in which a hydrocarbonfeed is reacted with hydrogen at elevated temperature and elevatedpressure (hydroprocessing reaction conditions), including hydrogenation,hydrodesulfurization, hydrodenitrogenation, hydrodemetallization,hydrodearomatization, hydroisomerization, hydrodewaxing, hydrocracking,and hydrocracking under mild pressure conditions, which is also referredto as mild hydrocracking.

More specifically, “hydroprocessing” as the term is employed hereinmeans oil refinery processes for reacting petroleum feedstocks (complexmixtures of hydrocarbon present in petroleum which are liquid atconditions of standard temperature and pressure) with hydrogen underpressure in the presence of a catalyst to lower: (a) the concentrationof at least one of sulfur, contaminant metals, nitrogen, and Conradsoncarbon, present in said feedstock, and (b) at least one of theviscosity, pour point, and density of the feedstock. Hydroprocessingincludes hydrocracking, isomerization/dewaxing, hydrofinishing, andhydrotreating processes which differ by the amount of hydrogen reactedand the nature of the petroleum feedstock treated.

Hydrofinishing is typically understood to involve the hydroprocessing ofhydrocarbonaceous oil containing predominantly (by weight of)hydrocarbonaceous compounds in the lubricating oil boiling range(“feedstock”) wherein the feedstock is contacted with solid supportedcatalyst at conditions of elevated pressure and temperature for thepurpose of saturating aromatic and olefinic compounds and removingnitrogen, sulfur, and oxygen compounds present within the feedstock, andto improve the color, odor, thermal, oxidation, and UV stability,properties of the feedstock.

Hydrocracking is typically understood to involve the hydroprocessing ofpredominantly hydrocarbonaceous compounds containing at least five (5)carbon atoms per molecule (“feedstock”) which is conducted: (a) atsuperatmospheric hydrogen partial pressure; (b) at temperaturestypically below 593.3° C. (1100° F.); (c) with an overall net chemicalconsumption of hydrogen; (d) in the presence of a solid supportedcatalyst containing at least one (1) hydrogenation component; and (e)wherein said feedstock typically produces a yield greater than about onehundred and thirty (130) moles of hydrocarbons containing at least aboutthree (3) carbon atoms per molecule for each one hundred (100) moles offeedstock containing at least five (5) carbon atoms per molecule.

Hydrotreating is typically understood to involve the hydroprocessing ofpredominantly hydrocarbonaceous compounds containing at least fivecarbon atoms per molecule (“feedstock”) for the desulfurization and/ordenitrification of said feedstock, wherein the process is conducted: (a)at superatmospheric hydrogen partial pressure; (b) at temperaturestypically below 593.3° C. (1100° F.); (c) with an overall net chemicalconsumption of hydrogen; (d) in the presence of a solid supportedcatalyst containing at least one hydrogenation component; and (e)wherein: (i) the feedstock produces a yield of typically from about 100to about 130 moles (inclusive) of hydrocarbons containing at least threecarbon atoms per molecule for each 100 moles of the initial feedstock;or (ii) the feedstock comprises at least 50 liquid volume percent ofundeasphalted residue typically boiling above about 565.6° C. (1050° F.)as determined by ASTM D-1160 Distillation and where the primary functionof the hydroprocessing is to desulfurize said feedstock; or (iii) thefeedstock is the product of a synthetic oil producing operation.

Isomerization/dewaxing is typically understood to involvehydroprocessing predominantly hydrocarbonaceous oil having a ViscosityIndex (VI) and boiling range suitable for lubricating oil (“feedstock”)wherein said feedstock is contacted with solid catalyst that contains,as an active component, microporous crystalline molecular sieve, atconditions of elevated pressure and temperature and in the presence ofhydrogen, to make a product whose cold flow properties are substantiallyimproved relative to said feedstock and whose boiling range issubstantially within the boiling range of the feedstock.

A further embodiment of the present invention is directed to a processfor the hydrotreating of a hydrocarbon feedstock in at least oneebullated bed reaction zone. More particularly, the hydrocarbonfeedstock is contacted with hydrogen in one or a series of ebullated bedreaction zones in the presence of a hydroprocessing catalyst comprisinga catalyst as described herein.

As is well known these feedstocks contain nickel, vanadium, andasphaltenes, e.g., about 40 ppm up to more than 1,000 ppm for thecombined total amount of nickel and vanadium and up to about 25 wt. %asphaltenes. Further, the economics of these processes desirably producelighter products as well as a demetallized residual by-product. Thisprocess is particularly useful in treating feedstocks with a substantialamount of metals containing 150 ppm or more of nickel and vanadium andhaving a sulfur content in the range of about 1 wt. % to about 10 wt. %.Typical feedstocks that can be treated satisfactorily by the process ofthe present invention contain a substantial amount (e.g., about 90%) ofcomponents that boil appreciably above 537.8° C. (1,000° F.). Examplesof typical feedstocks are crude oils, topped crude oils, petroleumhydrocarbon residua, both atmospheric and vacuum residua, oils obtainedfrom tar sands and residua derived from tar sand oil, and hydrocarbonstreams derived from coal. Such hydrocarbon streams containorganometallic contaminants which create deleterious effects in variousrefining processes that employ catalysts in the conversion of theparticular hydrocarbon stream being treated. The metallic contaminantsthat are found in such feedstocks include, but are not limited to, iron,vanadium, and nickel.

While metallic contaminants, such as vanadium, nickel, and iron, areoften present in various hydrocarbon streams, other metals are alsopresent in a particular hydrocarbon stream. Such metals exist as theoxides or sulfides of the particular metal, or as a soluble salt of theparticular metal, or as high molecular weight organometallic compounds,including metal naphthenates and metal porphyrins, and derivativesthereof.

Another characteristic phenomenon of hydrotreating heavy hydrocarbons isthe precipitation of insoluble carbonaceous substances from theasphaltenic fraction of the feedstock which cause operability problems.The amount of such sediment or insolubles formed increases with theamount of material boiling over 537.8° C. (1,000° F.) which is convertedor with an increase in the reaction temperature employed. Theseinsoluble substances, also known as Shell hot filtration solids, createthe operability difficulties for the hydroconversion unit and therebycircumscribe the temperatures and feeds the unit can handle. In otherwords, the amount of solids formed limit the conversion of a givenfeedstock operability difficulties as described above may begin tomanifest themselves at solids levels as low as 0.1 wt. %. Levels below0.5 wt. % are generally desired to prevent fouling of process equipment.A description of the Shell hot filtration test is found at A. J. J.,Journal of the Inst. of Petroleum (1951) 37, pp. 596-604 by VanKerkvoort, W. J. and Nieuwstad, A. J. J. which is incorporated herein byreference.

Hydrotreating operations are typically carried out in one or a series ofebullated bed reactors. As previously elucidated, an ebullated bed isone in which the solid catalyst particles are kept in random motion bythe upward flow of liquid and gas. An ebullated bed typically has agross volume of at least 10 percent greater and up to 70% greater thanthe solids thereof in a settled state. The required ebullition of thecatalyst particles is maintained by introducing the liquid feed,inclusive of recycle if any, to the reaction zone at linear velocitiesranging from about 0.02 to about 0.4 feet per second and preferably,from about 0.05 to about 0.20 feet per second.

The operating conditions for the hydrotreating of heavy hydrocarbonstreams, such as petroleum hydrocarbon residua and the like, are wellknown in the art and comprise a pressure within the range of about 1,000psia (68 atm) to about 3,000 psia (204 atm), an average catalyst bedtemperature within the range of about 700° F. (371° C.) to about 850° F.(454° C.), a liquid hourly space velocity (LHSV) within the range ofabout 0.1 volume of hydrocarbon per hour per volume of catalyst to about5 volumes of hydrocarbon per hour per volume of catalyst, and a hydrogenrecycle rate or hydrogen addition rate within the range of about 2,000standard cubic feet per barrel (SCFB) (356 m³/m³) to about 15,000 SCFB(2,671 m³/m³). Preferably, the operating conditions comprise a totalpressure within the range of about 1,200 psia to about 2,000 psia(81-136 atm); an average catalyst bed temperature within the range ofabout 730° F. (387° C.) to about 820° F. (437° C.); and a LHSV withinthe range of about 0.1 to about 4.0; and a hydrogen recycle rate orhydrogen addition rate within the range of about 5,000 SCFB (890 m³/m³)to about 10,000 SCFB (1,781 m³/m³). Generally, the process temperaturesand space velocities are selected so that at least 30 vol. % of the feedfraction boiling above 1,000° F. is converted to a product boiling below1,000° F. and more preferably so that at least 70 vol. % of the subjectfraction is converted to a product boiling below 1,000° F.

For the treatment of hydrocarbon distillates, the operating conditionswould typically comprise a hydrogen partial pressure within the range ofabout 200 psia (13 atm) to about 3,000 psia (204 atm); an averagecatalyst bed temperature within the range of about 600° F. (315° C.) toabout 800° F. (426° C.); a LHSV within the range of about 0.4 volume ofhydrocarbon per hour per volume of catalyst to about 6 volumes ofhydrocarbon recycle rate or hydrogen addition rate within the range ofabout 1,000 SCFB (178 m³/m³) to about 10,000 SCFB (1,381 m³/m³).Preferred operating conditions for the hydrotreating of hydrocarbondistillates comprise a hydrogen partial pressure within the range ofabout 200 psia (13 atm) to about 1,200 psia (81 atm); an averagecatalyst bed temperature within the range of about 600° F. (315° C.) toabout 750° F. (398° C.); a LHSV within the range of about 0.5 volume ofhydrocarbon per hour per volume of catalyst to about 4 volumes ofhydrocarbon per hour per volume of catalyst; and a hydrogen recycle rateor hydrogen addition rate within the range of about 1,000 SCFB (178m³/m³) to about 6,000 SCFB (1,068 m³/m³).

The most desirable conditions for conversion of a specific feed to apredetermined product, however, can be best obtained by converting thefeed at several different temperatures, pressures, space velocities andhydrogen addition rates, correlating the effect of each of thesevariables and selecting the best compromise of overall conversion andselectivity. The catalyst composition of the invention is particularlysuitable for hydrotreating heavy hydrocarbon feedstocks.

All parts and percentages in the examples, as well as in the remainderof the specification, are by weight unless otherwise specified.

EXAMPLES Stable Metals Solution and Catalyst Preparation Examples

Preparation of Impregnating Solution

Stable Metals Solution

Room temperature water (750 g) was placed in a glass kettle equippedwith an overhead stirrer. Nickel carbonate (40% Ni; 116 g) was added toform a slurry. To the stirring slurry was added 75% orthophosphoric acid(52 g). The slurry was then heated to 120° F. Molybdenum trioxide (588g) was added. After addition was complete, the temperature was raised to190° F. and held for three hours. The solution was allowed to cool; theresulting solution corresponds to Example 1A. Subsequent dilution of 1 Awith water to a final weight of 2280 g resulted in the solution ofExample 1B. The theoretical concentration of metals for the dilutedsolution are 17.2% Mo, 2.0% Ni and 0.5% P. Analysis of the solutionshowed 17.0% Mo, 2.2% Ni and 0.5% P.

Properties of Alumina Carrier Used to Prepare Catalysts

Alumina Properties For Catalyst Examples 1-3 Composition/PropertyAlumina Carrier Al₂O₃, wt. % >99 Na₂O, wt. % 0.03 SO₄, wt. % 0.70 TotalVolatiles at 1750° F., wt. % 34.2 Average Particle Size, μm 25 SurfaceArea, m²/g 303 Pore Volume, cc/g 0.93

Catalyst Example 1

Uncalcined pseudoboehmite alumina powder (5200 grams) was placed into a5-gallon Baker Perkins Sigma mixer. Stable metals solution (2562 g),prepared according to the method described above, was added with mixing.Nickel nitrate solution (15% Ni; 798 g) and water (1584 g) were alsoadded. The resulting material was mixed for 45 minutes. Themetals-containing alumina mixture was extruded through a 4″ Bonnotsingle auger type extruder. A die with nominal 1 mm holes was used toform the catalyst. The formed catalyst particles were dried at 250° F.for four hours then calcined at 1250° F. for one hour. The theoreticalconcentration of metals for this catalyst are 15.2% MoO₃, 5.0% NiO and0.7% P₂O₅. Analysis of the catalyst showed 14.7% MoO₃, 4.9% NiO and 0.5%P₂O₅.

Catalyst Example 2

Uncalcined pseudoboehmite alumina powder (5200 grams) was placed into a5-gallon Baker Perkins Sigma mixer. Stable metals solution (2515 g),prepared according to the method described above, was added with mixing.Nickel nitrate solution (15% Ni; 458 g) and water (1785 g) were alsoadded. The resulting material was mixed for 45 minutes. Themetals-containing alumina mixture was extruded through a 4″ Bonnotsingle auger type extruder. A die with nominal 1 mm holes was used toform the catalyst. The formed catalyst particles were dried at 250° F.for four hours then calcined at 1250° F. for one hour. The theoreticalconcentration of metals for this catalyst are 15.2% MoO₃, 3.6% NiO and0.7% P₂O₅. Analysis of the catalyst showed 14.7% MoO₃, 3.5% NiO and 0.7%P₂O₅.

Catalyst Example 3 (Comparative)

Uncalcined pseudoboehmite alumina powder (5200 grams) was placed into a5-gallon Baker Perkins Sigma mixer. A dilute nitric acid solutionprepared from 30 grams of 75% nitric acid and 1570 grams of water wasadded with mixing. After 15 minutes, an aqueous solution of ammoniumdimolybdate (18.8% Mo; 2270 g) was added and the resulting mixture wasmixed an additional 5 minutes. Nickel nitrate solution (15% Ni; 795 g)was added. The resulting material was mixed for 25 minutes. Themetals-containing alumina mixture was extruded through a 4″ Bonnotsingle auger type extruder. A die with nominal 1 mm holes was used toform the catalyst. The formed catalyst particles were dried at 250° F.for four hours then calcined at 1250° F. for one hour. The theoreticalconcentration of metals for this catalyst are 15.3% MoO₃ and 3.6% NiO.Analysis of the catalyst showed 14.7% MoO₃ and 3.5% NiO. The catalysthad the following properties: Surface area (m²/g)=334; Total pore volume(cc/g)=0.83; Pore volume>250 Å (cc/g)=0.24. The catalyst was prepared asfor Example 2 except using separate solutions of ammonium dimolybdateand nickel nitrate were used and no phosphoric acid was used.

ASI Properties of Catalysts

The catalyst samples prepared as described above were tested for ASIusing the method described above; the results are shown in the followingtable:

Sample ASI Catalyst Example 1 0.94 Catalyst Example 2 0.76 CatalystExample 3 0.62 (Comparative)

The results clearly show the advantage of the stable impregnatingsolution and the pre-impregnation method used to prepare the catalysts.

The catalyst samples for the pilot plant tests had the properties shownin the following table:

Invention Invention Comparative Example 1 Example 2 Pilot Plant SampleMoO₃ (wt. %) 14.7 14.7 14.4 NiO (wt. %) 4.9 3.5 3.3 Ni/Mo (mol/mol) 0.640.46 0.44 P₂O₅ (wt. %) 0.5 0.7 0.0 Surface Area (m²/g) 322 301 345 TotalPore Volume (cc/g) 0.79 0.83 0.82 Pore Vol. >250 Å (cc/g) 0.22 0.24 0.24

Preparation of the Comparative Pilot Plant Catalyst is as Follows:

A mixture is prepared using a quantity of an aqueous solution ofammonium dimolybdate, an aqueous solution of nickel nitrate, water,nitric acid, recycled fines and uncalcined pseudoboehmite aluminapowder. The components are fed to a mixer to combine these components inorder to form a homogeneous “damp mix” suitable for extrusion. Theextruded particles are dried at a temperature of about 110 to about 150°C., and then calcined at a temperature of about 500 to about 750° C. forabout one to about two hours.

Evaluation of Catalyst Performance

The properties of the hydrocarbon feedstock used in the pilot plantcatalyst evaluation are shown in the following table.

Hydrocarbon Feedstock Properties Type Arab Medium Vacuum Resid APIGravity 7.2 1000 deg F.+, wt. % 77.6 Sulfur, wt. % 4.86 Total Nitrogen,wppm 3428 MCR, wt. % 16.9 Pentane Insolubles, wt. % 12.8 HeptaneInsolubles, wt. % 6.1 Metals, wppm Ni 33.9 V 112.5 Na <1 D1160, vol %(deg F.) IBP 738  5% 853 10% 910 20% 989 30% 1039 40% 1082 50% 1092

Catalyst performance was evaluated in a fixed bed pilot plant using thefollowing operating conditions:

-   1. 100 cc of catalyst is charged to the reactor. (Reactor is 1 in.    diameter, 3 ft long, with 6 individual band heaters controlled by 6    thermocouples spaced along the reactor bed).-   2. The catalyst is heated to 350° F. in nitrogen and then hydrogen    at 300 psig and at 6.5 SCF/hr for leak test and catalyst dryout.-   3. The reactor temperature is raised to 450° F. (at 25 F/hr rate)    with H₂ rate at 6.5 SCF/hr and 1 wt % DMDS in heptane (sulfiding    solution) at 145 cc/hr to start sulfiding. After 18 hours,    temperature is raised to 650° F. (at 25 F/hr rate) and 6 wt % DMDS    in heptane is used at 145 cc/hr for 10 hours. Sulfiding is    essentially complete after this step.-   4. The unit is pressured with H₂ to 2000 psig. The H₂ flow rate is    set at 5000 SCF/bbl of feedstock when operating at a Liquid Hourly    Space Velocity (LHSV) of 0.97.-   5. The catalyst bed temperature is raised to 680° F. (at 50 F/hr)    with the feedstock which is then introduced at 0.97 LHSV.-   6. After 24 hours on feedstock, the temperature is raised to the    desired operating temperature (795-805° F.).-   7. The liquid product is collected daily and analyzed for API,    sulfur, MCR, nitrogen, metals, 1000 F+ and sediment.

MCR=micro carbon residue and is described in ASTM Method D4530.Sediment, test method ASTM D4870; a reference to this test appears inU.S. Pat. No. 5,928,499 (Column 13, lines 31-42). In the figureillustrating sediment vs. conversion, FIG. 3, the dotted line separatesdata collected at 795° F. (left) from data collected at 805° F. (right).As for sediment, sediment is the insoluble material (captured byfiltration) that is found in the feed or product. This is to becontrasted with carbon residue which is the material left afterpyrolyzing the feed or product. The sediment level for the residfeedstocks typically is very low. There are both sediment molecules andsediment precursor molecules in the feed, but the sediment molecules aresoluble in the feed and therefore are not captured via filtration. Uponconversion of the 1000° F.+ materials, the sediment precursor moleculesbecome sediment molecules, and it is believed that the solubilityproperties of the product are diminished compared to the feed.Therefore, more severe operations lead to higher observed sediment. Lesssediment is observed with better performing catalysts and this isbelieved due to either production of less sediment molecules orconversion of the feed in such a way that the products have bettersolubility properties, or both.

Percent conversion for all parameters is calculated using the followingequation:[(amount X in feed−amount X in product)/amount X in feed]*100

For example, for 1000° F.+ conversion, it would be the volume of 1000°F.+ boiling material in the feed (for a certain period of timecorresponding to the balance period being considered for the pilotplant) minus the volume of 1000° F.+ boiling material in the product(over that same period of time), this quantity divided by the volume of1000° F.+ boiling material in the feed, all times 100. The samecalculation procedure is used for sulfur and MCR.

Performance of the catalysts is shown in FIGS. 1, 2 and 3. In eachinstance it can be seen that the catalyst examples of the inventionperformed better than the comparative catalyst: improved sulfurconversion, particularly at extended run length; improved microcarbonresidue conversion; and reduced sediment versus 1000° F.+ conversion.Typical results at equivalent conversion were as follows:

HDS 1000° F.+ Catalyst Conversion (%)* Conversion (%) Sediment (ppmw)Ex. 1 85 59 3000 Ex. 2 83 61 4000 Comparative 79 60 6000 *atapproximately 180 hrs. on feed (FIG. 2)

Any range of numbers recited in the specification, or paragraphshereinafter, describing various aspects of the invention, such as thatrepresenting a particular set of properties, units of measure,conditions, physical states or percentages, is intended literally toincorporate expressly herein by reference or otherwise, any numberfalling within such range, including any subset of numbers or rangessubsumed within any range so recited. Additionally, the term “about”when used as a modifier for, or in conjunction with, a variable, isintended to convey that the values and ranges disclosed herein areflexible and that practice of the present invention by those skilled inthe art using, e.g., temperatures, concentrations, amounts, contents,carbon numbers, properties such as viscosity, particle size, surfacearea, solubility, etc., that are outside of the stated range ordifferent from a single value, will achieve the desired result, namely,preparation of aqueous compositions useful for impregnating foraminouscarriers, methods of impregnating such carriers, the catalysts obtainedthereby and the use of such catalysts in hydroconversion processes.

The principles, preferred embodiments, and modes of operation of thepresent invention have been described in the foregoing specification.The invention which is intended to be protected herein, however, is notto be construed as limited to the particular forms disclosed, sincethese are to be regarded as illustrative rather than restrictive.Variations and changes may be made by those skilled in the art, withoutdeparting from the spirit of the invention.

1. A catalyst prepared by impregnation of a catalyst carrier with astabilized aqueous composition according to use of any one of themethods set forth in the following enumerated Paragraphs 1 through 15and including the step of separating the volatile portion of saidsolution from the impregnated uncalcined carrier to obtain a driedcatalyst having a desired moisture content: Paragraph 1: A method ofpreparing stabilized aqueous compositions for use in impregnatingcatalyst carriers to produce catalyst precursors and catalysts,comprising adding to a suitable quantity of water: (A) at least onesubstantially water insoluble Group VIII metal component; and (B) atleast one substantially water-soluble, phosphorous-containing acidiccomponent in an amount insufficient to cause dissolution of said GroupVIII metal component so as to produce a slurry, and combining saidslurry with: (C) at least one Group VIB metal component; and (D) mixingthe combination of (A), (B) and (C) and heating the mixture, for a timeand to a temperature sufficient for (A), (B) and (C) to form a solution;and (E) adding an additional amount of water, if required, to obtainsolution concentrations of said at least one Group VIII metal, said atleast one Group VIB metal and phosphorous useful for impregnating saidcarriers; wherein Group VIB and Group VIII refer to Groups of theperiodic table of the elements; Paragraph 2: The method according toParagraph 1 wherein the amount of said phosphorous-containing acidiccomponent provides a phosphorous to Group VIB metal molar ratio of about0.05 to less than about 0.25; Paragraph 3: The method according toParagraph 1 wherein said molar ratio of Group VIII metal to Group VIBmetal is about 0.05 to about 0.45; Paragraph 4: The method according toParagraph 1 wherein the concentration of said Group VIB metal is about 3to about 50 weight percent; Paragraph 5: The method according toParagraph 1 wherein said Group VIII metal component is selected from thegroup consisting of nickel carbonate and cobalt carbonate; Paragraph 6:The method according to Paragraph 1 further comprising adding an elementfrom Group VIII in the form of a substantially water-soluble componentto provide a molar ratio of total Group VIII metal to Group VIB metal ofabout 0.05 to about 1.0; Paragraph 7: The method according to Paragraph6 wherein said Group VIII metal component is nickel nitrate; Paragraph8: The method according to Paragraph 1 or Paragraph 12 wherein saidacidic component is orthophosphoric acid; Paragraph 9: The methodaccording to Paragraph 1 or Paragraph 14 wherein said Group VIB metal isselected from molybdenum or tungsten; Paragraph 10: The method accordingto Paragraph 9 wherein said acidic component is orthophosphoric acid;Paragraph 11: The method according to Paragraph 9 wherein said Group VIBmetal is molybdenum; Paragraph 12: The method according to Paragraph 1wherein the amount of said phosphorous-containing acidic componentprovides a phosphorous to Group VIB metal molar ratio of about 0.09 toabout 0.18; Paragraph 13: The method according to Paragraph 1 whereinsaid molar ratio of Group VIII metal to Group VIB metal is about 0.10 toabout 0.25; Paragraph 14: The method according to Paragraph 1 whereinthe concentration of said Group VIB metal is about 3.5 to about 42weight percent; Paragraph 15: The method according to Paragraph 1further comprising adding an element from Group VIII in the form of asubstantially water-soluble component to provide a molar ratio of totalGroup VIII metal to Group VIB metal of about 0.30 to about 0.9.
 2. Thecatalyst according to claim 1 wherein said carrier is selected from thegroup consisting of alumina, silica, silica-alumina, natural clay,synthetic clay and mixtures thereof.
 3. The catalyst according to claim2 wherein said carrier is alumina.
 4. The catalyst according to claim 1and further including the step of forming or shaping the impregnatedcatalyst carrier.
 5. The catalyst according to any one of claims 1 to 4and further including the step of calcining the dried catalyst.
 6. Thecatalyst according to any one of claims 1 to 4, having been calcined anddried, useful in hydroprocessing a petroleum feed, said catalystcomprising at least one catalytically active metal from Group VIB of theperiodic table, at least one catalytically active metal from Group VIIIof the periodic table, and phosphorous, wherein said metals andphosphorous are carried on a foraminous carrier, wherein the pore modeis about 40 to about 90Å, wherein the loss in weight on ignition at1000° F. to 1200° F. of said catalyst is less than about 5 wt.% based onthe weight of the catalyst, and wherein the ASI ratio is greater thanabout 0.75 to about 2.0.
 7. The catalyst according to any one of claims1 to 4, having been calcined and dried, useful in hydrodesulfurization,hydrodenitrification and hydrodemetallation of heavy hydrocarbons, saidcatalyst comprising at least one catalytically active metal from GroupVIB of the periodic table, at least one catalytically active metal fromGroup VIII of the periodic table, and phosphorous, wherein said metalsand phosphorous are carried on a foraminous carrier, wherein the poremode is about 40 to about 90Å, wherein the loss in weight on ignition at1000° F. to 1200° F. of said catalyst is less than about 5 wt.% based onthe weight of the catalyst and wherein the ASI ratio is greater thanabout 0.75 to about 2.0.
 8. The catalyst according to any one of claims1 to 4, having been calcined and dried, characterized by its ability tohydrotreat a charge hydrocarbon feed containing components boiling above1000° F, and sediment-formers, sulfur compounds, metals, asphaltenes,carbon residue, and nitrogen compounds, said catalyst comprising atleast one catalytically active metal from Group VIB of the periodictable, at least one catalytically active metal from Group VIII of theperiodic table, and phosphorous, wherein said metals and phosphorous arecarried on a foraminous carrier, wherein the pore mode is about 40 toabout 90 Å wherein the loss in weight on ignition at 1000° F. to 1200°F. of said catalyst is less than about 5 wt.% based on the weight of thecatalyst and wherein the AST ratio is greater than about 0.75 to about2.0.
 9. A catalyst prepared by impregnation of a catalyst carrier with astabilized aqueous composition according to use of any one of thecompositions set forth in the following enumerated Paragraphs 1 through14 and including the step of separating the volatile portion of saidsolution from the impregnated uncalcined carrier to obtain a driedcatalyst having a desired moisture content: Paragraph 1: A stabilizedcomposition for use in impregnating catalyst carriers comprising: (A)water; (B) catalytically active metals being in the form of andcomprising: (1) at least one component providing at least one metal fromGroup VIB of the periodic table; and (2) at least one componentproviding at least one metal from Group VIII of the periodic table;wherein (i) said Group VIII metal is provided by a substantially waterinsoluble component; (ii) the molar- ratio of said Group VIII metal toGroup VIB metal is about 0.05 to about 0.45, provided that the amount ofsaid Group VIII metal is sufficient to promote the catalytic effect ofsaid Group VIB metal; (iii) the concentration of said Group VIB metal,expressed as the oxide, is at least about 3 to about 50 weight percentbased on the weight of said composition; and (C) at least onesubstantially water-soluble, phosphorous-containing acidic component inan amount insufficient to solubilize said Group VIII metal at ambienttemperature and sufficient to provide a phosphorous to Group VIB metalmolar ratio of about 0.05 to less than about 0.25; Paragraph 2: Acomposition according to Paragraph 1 wherein said molar ratio of GroupVIII metal to Group VIB metal is about 0.05 to about 0.40; Paragraph 3:A composition according to Paragraph 1 wherein the concentration of saidGroup VIB metal is about 3 to about 50 weight percent; Paragraph 4: Acomposition according to Paragraph 1 wherein said molar ratio ofphosphorous to Group VIB metal is about 0.07 to about 0.23; Paragraph 5:A composition according to any one of Paragraphs 1 to 4 wherein saidGroup VIII component is selected from the group consisting of a nickelcarbonate and cobalt carbonate; Paragraph 6: A composition according toParagraph 1 further comprising an additional amount of an element fromGroup VIII in the form of a substantially water-soluble component toprovide a molar ratio of total Group VIII metal to Group VIB metal ofabout 0.05 to about 1.0; Paragraph 7: A composition according toParagraph 2 wherein said component of a Group VIII metal is nickelcarbonate; Paragraph 8:A compositionaccording to Paragraph 6 whereinsaidsubstantiallywater-soluble component is nickel nitrate; Paragraph 9:A composition according to Paragraph 1 wherein said acidic component isorthophosphoric acid; Paragraph 10: A composition according to any ofParagraphs 1 through 4, 6 and 7 wherein said Group VIB metal is selectedfrom molybdenum or tungsten; Paragraph 11: A composition according toParagraph 1 wherein said molar ratio of Group VIII metal to Group VIBmetal is about 0.10 to about 0.25; Paragraph 12: A composition accordingto Paragraph 1 wherein the concentration of said Group VIB metal isabout 3.5 to about 42 weight percent; Paragraph 13: A compositionaccording to Paragraph 1 wherein said molar ratio of phosphorous toGroup VIB metal is about 0.09 to about 0.18; Paragraph 14: A compositionaccording to Paragraph 1 further comprising an additional amount of anelement from Group VIII in the form of a substantially water-solublecomponent to provide a molar ratio of total Group VIII metal to GroupVIB metal of about 0.30 to about 0.9.
 10. The catalyst according toclaim 9 wherein said carrier is selected from the group consisting ofalumina, silica, silica-alumina, natural clay, synthetic clay andmixtures thereof.
 11. The catalyst according to claim 10 wherein saidcarrier is alumina.
 12. The catalyst according to claim 9 and furtherincluding the step of forming or shaping the impregnated catalystcarrier.
 13. The catalyst according to any one of claims 9 to 12 andfurther including the step of calcining the dried catalyst.
 14. Thecatalyst according to any one of claims 9 to 12, having been calcinedand dried, useful in hydroprocessing a petroleum feed, said catalystcomprising at least one catalytically active metal from Group VIB of theperiodic table, at least one catalytically active metal from Group VIIIof the periodic table, and phosphorous, wherein said metals andphosphorous are carried on a foraminous carrier, wherein the pore modeis about 40 to about 90Å, wherein the loss in weight on ignition at1000° F. to 1200° F. of said catalyst is less than about 5 wt.% based onthe weight of the catalyst, and wherein the ASI ratio is greater thanabout 0.75 to about 2.0.
 15. The catalyst according to any one of claims9 to 12, having been calcined and dried, useful in hydrodesulfurization,hydrodenitrification and hydrodemetallation of heavy hydrocarbons, saidcatalyst comprising at least one catalytically active metal from GroupVIB of the periodic table, at least one catalytically active metal fromGroup VIII of the periodic table, and phosphorous, wherein said metalsand phosphorous are carried on a foraminous carrier, wherein the poremode is about 40 to about 90Å, wherein the loss in weight on ignition at1000° F. to 1200° F. of said catalyst is less than about 5 wt.% based onthe weight of the catalyst and wherein the ASI ratio is greater thanabout 0.75 to about 2.0.
 16. The catalyst according to any one of claims9 to 12, having been calcined and dried, characterized by its ability tohydrotreat a charge hydrocarbon feed containing components boiling above1000° F., and sediment-formers, sulfur compounds, metals, asphaltenes,carbon residue, and nitrogen compounds, said catalyst comprising atleast one catalytically active metal from Group VIB of the periodictable, at least one catalytically active metal from Group VIII of theperiodic table, and phosphorous, wherein said metals and phosphorous arecarried on a toraminous carrier, wherein the pore mode is about 40 toabout 90Å wherein the loss in weight on ignition at 1000° F. to 1200° F.of said catalyst is less than about 5 wt.% based on the weight of thecatalyst and wherein the ASI ratio is greater than about 0.75 to about2.0.